Oil level gauge guide of engine

ABSTRACT

An oil level gauge guide includes a cylindrical portion, a first pipe, and a second pipe. The cylindrical portion is provided on a crank case wall which defines a crank chamber including an oil reservoir of an engine, and includes a through hole which communicates the interior and exterior of the crank chamber with each other. The first pipe includes a first end held by the cylindrical portion, and a second end extending outside the crank chamber and fixed to the engine. The second pipe includes a first end held by the cylindrical portion, and a second end extending to the bottom of the crank chamber and fixed to the engine. The oil level gauge guide uses an arrangement pointing toward the lowermost portion of an oil pan, and yet has a high degree of freedom of the attaching position.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to Japanese Patent Application No. 2016-140108 filed on Jul. 15, 2016, the entire contents of which application are hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an engine oil level gauge guide that holds an oil level gauge of an engine.

2. Description of the Related Art

There is always a demand that automobile engines are to be made more compact. In an engine of this type, engine accessories are arranged close to a cylinder block, and an oil level gauge is arranged so as to avoid the engine accessories. The oil level gauge is used to check the amount of oil stored in a crank chamber of the engine, and is retractably inserted into and held in an oil level gauge guide provided on the cylinder body side. An example of a conventional oil level gauge guide is disclosed in Japanese Patent Laid-Open No. 2007-231904.

This oil level gauge guide disclosed in Japanese Patent Laid-Open No. 2007-231904 is formed by a straight pipe. The oil level gauge guide is fixed to the cylinder block in a state in which the lower part of the guide projects into the crank chamber through a through hole in the cylinder block. The lower end of the oil level gauge guide points toward the bottom of an oil pan.

Generally, the oil level gauge guide has a function as a guide to lead an oil change hose to the bottom of the oil pan, in addition to the function of holding the oil level gauge. The oil change hose is used to draw out and discharge engine oil remaining in the lowermost portion of the oil pan. Accordingly, the oil level gauge guide is arranged in a position in which the oil level gauge guide points toward the lowermost portion of the oil pan as the oil level gauge guide avoids obstacles in the oil pan.

In the conventional oil level gauge guide disclosed in Japanese Patent Laid-Open No. 2007-231904, there is a problem that it is difficult to make the engine more compact. This is because the position of the oil level gauge guide is restricted. To make the engine compact, it is effective to arrange accessories close to the cylinder block. However, the oil level gauge guide has to be arranged in a position that allows the lower end of the oil level gauge guide to point toward the lowermost portion of the oil pan as the oil level gauge guide avoids obstacles in the oil pan.

As the engine accessories and oil level gauge interfere with each other, it becomes a hindrance in making the engine more compact. Note that it may be possible to change the position of the oil level gauge guide and avoid the interference by bending the upper portion of the oil level gauge guide extending outside the crank chamber and the lower portion thereof in the crank chamber. However, the oil level gauge guide bent like this cannot be inserted into the through hole of the cylinder block.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide oil level gauge guides in which a lower end of the oil level gauge guide points toward the lowermost portion of an oil pan, and yet has a high degree of freedom of the attaching position of the oil level gauge guide.

According to a preferred embodiment of the present invention, an oil level gauge guide of an engine includes a cylindrical or substantially cylindrical portion (hereinafter, cylindrical portion) provided on a wall that defines a crank chamber including an oil reservoir of the engine, the cylindrical portion including a through hole that allows the interior and exterior of the crank chamber to communicate with each other, a first pipe including a first end held by the cylindrical portion, and a second end extending outside the crank chamber and fixed to the engine, and a second pipe including a first end held by the cylindrical portion, and a second end extending to the bottom of the crank chamber and fixed to the engine.

The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing a structure of an engine including an oil level gauge guide according to a preferred embodiment of the present invention.

FIG. 2 is a sectional view showing main portions in an enlarged scale.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Oil level gauge guides of engines according to preferred embodiments of the present invention will be explained in detail below with reference to FIGS. 1 and 2.

An engine 1 shown in FIG. 1 is preferably an automobile engine, for example, and is mounted in a vehicle body (not shown) in a state in which an oil pan 2 shown in the lowermost position in FIG. 1 is positioned in the lower portion of the vehicle body. For the sake of convenience, the right side of the engine 1 in FIG. 1 will be called one side, and the left side of the engine 1 will be called the other side.

The oil pan 2 preferably has a box shape which opens upward, and is attached to the lower end portion of a cylinder block 3. An oil pump 4 is accommodated in the oil pan 2, and engine oil is stored in the oil pan 2. The interior of the oil pan 2 defines an oil reservoir 5 of the engine 1. An oil drain bolt 6 is threadably provided near the bottom of the oil pan 2.

The oil pump 4 is supported by the lower end portion of the cylinder block 3 via a bracket (not shown). The oil pump 4 draws up engine oil 7 in the oil pan 2 and supplies the engine oil 7 to portions of the engine 1 to be lubricated.

The cylinder block 3 includes a crank case wall 11 preferably having a box shape which opens downward, and a cylinder unit 12 extending upward from the crank case wall 11.

The crank case wall 11 closes the opening of the oil pan 2. A crank chamber 13 that includes the oil reservoir 5 is located between the crank case wall 11 and the oil pan 2.

The crank case wall 11 includes a cylindrical portion 15 that defines a portion of an oil level gauge guide 14 (to be described below). The crank case wall 11 is a wall that defines a crank chamber in a preferred embodiment of the present invention.

A crank shaft 16 is accommodated in the crank chamber 13.

A starter motor 17 is located on one side of the crank case wall 11. The starter motor 17 is attached to a bracket 18 provided in one end (the end positioned behind the drawing surface of FIG. 1) of the crank case wall 11 in the axial direction of the crank shaft 16 (the direction perpendicular to the drawing surface of FIG. 1). The starter motor 17 is attached to the bracket 18 by locating the starter motor 17 toward the bracket 18 from the other side (the side positioned forward of the drawing surface of FIG. 1) in the axial direction of the crank shaft 16.

A plurality of cylinder holes 21 are provided in the cylinder unit 12. Pistons 22 movably fit in the cylinder holes 21. Each piston 22 is connected to the crank shaft 16 by a connecting rod 23. On one side of the cylinder unit 12, a surge tank 24 (to be described below) and an alternator 25 are provided. The alternator 25 is supported by the other end (the end forward of the drawing surface of FIG. 1) of the cylinder block 3 in the axial direction of the crank shaft 16 via a bracket (not shown).

The cylinder holes 21 open in the upper end of the cylinder unit 12, and are closed by a cylinder head 26.

Although details are not shown, the cylinder head 26 includes an intake valve, an exhaust valve, valve gears that drive these valves, and the like. An intake manifold 27 is attached to one side of the cylinder head 26, and an exhaust device (not shown) is attached to the other side thereof. A head cover 28 is attached to the upper end of the cylinder head 26.

The intake manifold 27 guides intake air to all of the cylinders from the surge tank 24 positioned on one side of the cylinder unit 12.

The oil level gauge guide 14 is an element of the engine that includes a function of holding an oil level gauge 31, and a function of guiding an oil change hose 32 to a lowermost portion 2 a of the oil pan 2 to change engine oil. The oil level gauge guide 14 includes the cylindrical portion 15 provided on the crank case wall 11, a first pipe 33 extending upward from the cylindrical portion 15, and a second pipe 34 extending downward from the cylindrical portion 15.

The oil level gauge 31 includes a narrow band-shaped main gauge body 31 a inserted into the oil level gauge guide 14, and a ring 31 b provided on one end (the upper end) of the main gauge body 31 a. The oil level gauge 31 is held by the oil level gauge guide 14 such that the ring 31 b is extends out of the upper end of the first pipe 33.

The lower end of the main gauge body 31 a projects downward from the second pipe 34, and enters the engine oil 7. When the engine 1 is not in operation, a liquid surface L of the engine oil 7 is positioned lower than the lower end of the oil level gauge guide 14.

The ring 31 b is used by a person who puts his or her finger in it to pull out or insert the main gauge body 31 a from or into the oil level gauge guide 14 when checking the storage amount of the engine oil 7.

One end of the oil change hose 32 is connected to an oil suction device (not shown), and the other end portion thereof is inserted into the oil level gauge guide 14 in this state. When the suction device operates in a state in which the distal end of the oil change hose has reached the lowermost portion 2 a of the oil pan 2, the engine oil 7 remaining at the bottom of the oil pan 2 is drawn out by the oil change hose 32.

The cylindrical portion 15 is preferably integral with the crank case wall 11. As shown in FIG. 2, the cylindrical portion 15 includes a first cylindrical portion 41 projecting from the crank case wall 11 to the side opposite to the crank chamber 13, and a second cylindrical portion 42 projecting into the crank chamber 13 from the crank case wall 11.

As shown in FIG. 1, the cylindrical portion 15 according to the present preferred embodiment is positioned closer to the cylinder unit 12 than the starter motor 17 when viewed in the axial direction of the crank shaft 16. Since the cylindrical portion 15 is located in this position, the first pipe 33 (to be described below) is not an obstacle when the starter motor 17 is assembled in the engine 1.

As shown in FIG. 2, the cylindrical portion 15 includes a through hole 43 which communicates the interior and exterior of the crank chamber 13 with each other. The through hole 43 includes a first hole 44 in the first cylinder 41, a second hole 45 in the second cylinder 42, and a communication hole 46 that connects the first hole 44 and the second hole 45.

The first hole 44 and the second hole 45 preferably have the same diameter, and are aligned on the same axis. The diameter of the communication hole 46 is preferably smaller than the diameter of each of the first hole 44 and the second hole 45.

The boundary portion between the first hole 44 and the communication hole 46 includes a first tapered surface 47 which gradually decreases in diameter in the direction from the first hole 44 to the communication hole 46.

The boundary portion between the communication hole 46 and the second hole 45 includes a second tapered surface 48 which gradually increases in diameter in the direction from the communication hole 46 to the second hole 45.

The first pipe 33 is preferably made by bending a metal pipe having a circular or substantially circular cross-section into a predetermined shape. One end (the lower end) of the first pipe 33 is held by the cylindrical portion 15, and the other end thereof extends outside the crank chamber 13. The other end of the first pipe 33 is fixed to the cylinder unit 12 by a first support stay 49 (see FIG. 1).

The first pipe 33 according to the present preferred embodiment includes a first straight pipe 51 extending upward and parallel or substantially parallel to an axis C of the cylinder unit 12 from the crank case wall 11, and a second straight pipe 53 connected to the first straight pipe 51 by a first curved portion 52.

As shown in FIG. 2, the first straight pipe 51 is inserted into the first hole 44 of the cylindrical portion 15 from above. The distal end of the first straight pipe 51 preferably has a bellow shape, for example, by pressure forming, and includes a first large diameter portion 51 a and a second large diameter portion 51 b. The outer diameter of the first and second large diameter portions 51 a and 51 b is preferably larger than the outer diameter of the rest of the first pipe 33, and smaller than the diameter of the first hole 44.

Of the first and second large diameter portions 51 a and 51 b, the first large diameter portion 51 a positioned at the distal end of the first straight pipe 51 includes a third tapered surface 54 pointing toward the communication hole 46. The third tapered surface 54 defines the opening edge of one end of the first pipe 33, and preferably has a shape which gradually increases in diameter toward the communication hole 46 (toward the distal end of the first straight pipe 51).

A first annular groove 55 is located between the first and second large diameter portions 51 a and 51 b. A first O-ring 56 is fitted in the first annular groove 55. The first O-ring 56 is compressed between the first annular groove 55 and the wall of the first hole 44. Accordingly, the first straight pipe (the lower end portion of the first pipe 33) is held in the first hole 44 by the first O-ring 56.

As shown in FIG. 1, the first curved portion 52 is positioned on one side of the cylinder unit 12, and includes an upper end which is bent diagonally upward so as to point toward one side of the engine 1. The second straight pipe 53 extends from the first curved portion 52 to one side of the cylinder head 26. The upper end of the second straight pipe 53 is located in a position which is opposite to the alternator 25 in the axial direction of the crank shaft 16, and overlaps the intake manifold 27 when viewed in the axial direction of the crank shaft 16. The first support stay 49 is, for example, welded to the second straight pipe 53.

The second pipe 34 is preferably made by bending a pipe identical or similar to the first pipe 33 into a predetermined shape. One end (the upper end) of the second pipe 34 is held by the cylindrical portion 15, and the other end thereof extends toward the bottom of the crank chamber 13. The other end of the second pipe 34 is fixed to the oil pump 4 via the second support stay 57. That is, the other end of the second pipe 34 is fixed to the engine 1.

The second pipe 34 according to the present preferred embodiment includes a third straight pipe 61 extending downward parallel or substantially parallel to the axis C of the cylinder unit 12 from the crank case wall 11, and a fourth straight pipe 63 connected to the third straight pipe 61 by a second curved portion 62.

As shown in FIG. 2, the third straight pipe 61 is inserted into the second hole 45 of the cylindrical portion 15 from below. Like the first straight pipe 51, the distal end portion of the third straight pipe 61 preferably has a bellows shape, for example, by pressure forming, and includes a third large diameter portion 61 a and a fourth large diameter portion 61 b.

The outer diameter of the third and fourth large diameter portions 61 a and 61 b is preferably larger than the outer diameter of the rest of the second pipe 34, and smaller than the diameter of the second hole 45. Of the third and fourth large diameter portions 61 a and 61 b, the third large diameter portion 61 a positioned at the distal end of the third straight pipe 61 includes a fourth tapered surface 64 pointing toward the communication hole 46. The fourth tapered surface 64 defines the opening edge of one end of the second pipe 34, and preferably has a shape which gradually increases in diameter toward the communication hole 46 (toward the distal end of the third straight pipe 61).

A second annular groove 65 is located between the third and fourth large diameter portions 61 a and 61 b. A second O-ring 66 is fitted in the second annular groove 65. The second O-ring 66 is compressed between the second annular groove 65 and the wall of the third hole. Accordingly, the third straight pipe 61 (the upper end portion of the second pipe 34) is held in the second hole 45 by the second O-ring 66.

As shown in FIG. 1, the second curved portion 62 is positioned between the oil pump 4 and an inclined side wall 67 of the oil pan 2, and includes a lower end which is bent along the side wall 67 of the oil pan 2. The side wall 67 of the oil pan 2 inclines downward so as to gradually approach the other side of the engine 1, when viewed in the axial direction of the crank shaft 16.

The fourth straight pipe 63 extends toward the lowermost portion 2 a of the oil pan 2 from the second curved portion 62. The second support stay 57 is, for example, welded to the fourth straight pipe 63.

The first pipe 33 of the oil level gauge guide 14 is attached to the engine 1 outside the crank chamber 13. This attachment is performed by inserting one end (the lower end) of the first pipe 33 into the first hole 44 with the first O-ring 56 fitted therein, and fixing the first support stay 49 to the cylinder unit 12 after that. Thus, the first pipe 33 is attached to the engine 1 separately from the second pipe 34 in the crank chamber 13, so that the first pipe 33 has a shape described above. More specifically, this shape extends along the cylinder unit 12 while avoiding interference with, e.g., the accessories (for example, the starter motor 17 and the alternator 25) of the engine 1 and other obstacles (for example, the intake manifold 27).

The second pipe 34 is attached to the engine 1 from the crank chamber side with the oil pan 2 being unattached to the crank case wall 11. The attachment of the second pipe 34 is performed by inserting one end (the upper end) of the second pipe 34 into the second hole 45 with the second O-ring 66 fitted therein, and fixing the second support stay 57 to the oil pump 4 after that. Therefore, the second pipe 34 has a shape by which the lower end points toward the lowermost portion 2 a of the oil pan 2 while avoiding the accessory (for example, the oil pump 4) in the crank chamber 13 and other obstacles.

Accordingly, the above-described preferred embodiments provide an oil level gauge guide 14 in which the second pipe 34 points toward the lowermost portion 2 a of the oil pan 2, and yet has a high degree of freedom of the attaching position. The accessories (for example, the starter motor 17 and the alternator 25) of the engine 1 including the oil level gauge guide 14 are thus able to be located near the engine 1 while avoiding interference with the oil level gauge guide 14. Consequently, the engine 1 is made more compact by using the oil level gauge guide 14 according to the preferred embodiments described above.

The cylindrical portion 15 according to a preferred embodiment preferably includes the first hole 44 into which the first pipe 33 is inserted, the second hole 45 into which the second pipe 34 is inserted, and the communication hole 46 that connects the first and second holes 44 and 45. The first pipe 33 is held in the first hole 44 by the first O-ring 56, and the second pipe 34 is held in the second hole 45 by the second O-ring 66.

In the preferred embodiments described above, one end of the first pipe 33 and one end of the second pipe 34 are elastically supported by the cylindrical portion 15 via the first and second O-rings 56 and 66, respectively, without any contact between them.

Although the oil level gauge guide 14 is divided into the first and second pipes 33 and 34, the work of attaching the oil level gauge guide 14 to the engine 1 is easily performed. In addition, the above described preferred embodiments also prevent the first and second pipes 33 and 34 from being worn by metal contact or generating noise and vibrations.

The communication hole 46 according to a preferred embodiment preferably has a diameter smaller than a diameter of each of the first and second holes 44 and 45. The boundary portion between the first hole 44 and the communication hole 46 preferably includes the first tapered surface 47. One end (the upper end) of the second pipe 34 preferably includes the fourth tapered surface 64.

Accordingly, in the process of inserting the oil level gauge 31 and oil change hose 32 into the oil level gauge guide 14, it is possible to prevent the distal ends of these inserted components from being caught by the connector between the first and second pipes 33 and 34 and preventing insertion of these components.

That is, if these inserted components come into contact with the first tapered surface 47 when entering the through hole 43 from the first pipe 33, the advancing direction is changed toward the center of the through hole 43. Also, if these inserted components come into contact with the fourth tapered surface 64 when entering the second pipe 34 from the through hole 43, the advancing direction is changed toward the center of the second pipe 34.

Even when the first and second pipes 33 and 34 have highly bent shapes, the oil level gauge 31 and oil change hose 32 are smoothly guided into the crank chamber 13, so the degree of freedom of the position of the oil level gauge guide 14 further increases.

In a preferred embodiment of the present invention, the first pipe is preferably attached to the engine outside the crank chamber, and the second pipe is preferably attached to the engine inside the crank chamber. Therefore, the first pipe has a shape extending along the cylinder while avoiding interference with the engine accessories and other obstacles. The second pipe has a shape in which the lower end points toward the lowermost portion of the oil pan, while avoiding interference with accessories and other obstacles in the crank chamber.

Accordingly, preferred embodiments of the present invention provide an oil level gauge guide in which the lower end of an oil level gauge points toward the lowermost portion of an oil pan, and yet has a high degree of freedom of the attaching position. The accessories of an engine including the above-described oil level gauge guide are located closer to the engine while avoiding interference with the oil level gauge guide. As a consequence, the engine is made more compact by using the oil level gauge guide according to preferred embodiments of the present invention.

While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims. 

What is claimed is:
 1. An oil level gauge guide of an engine, the oil level gauge guide comprising: a cylindrical or substantially cylindrical portion provided on a wall that defines a crank chamber including an oil reservoir of the engine, the cylindrical or substantially cylindrical portion including a through hole that allows an interior and an exterior of the crank chamber to communicate with each other; a first pipe including a first end held by the cylindrical or substantially cylindrical portion, and a second end extending outside the crank chamber and fixed to the engine; and a second pipe including a first end held by the cylindrical or substantially cylindrical portion, and a second end extending to a bottom of the crank chamber and fixed to the engine.
 2. The oil level gauge guide of the engine according to claim 1, wherein the through hole of the cylindrical or substantially cylindrical portion includes: a first hole into which the first pipe is inserted; a second hole into which the second pipe is inserted; a communication hole that connects the first hole and the second hole; and first and second O-rings respectively fitted on the first end of the first pipe and the first end of the second pipe; wherein the first pipe is held in the first hole by the first O-ring; and the second pipe is held in the second hole by the second O-ring.
 3. The oil level gauge guide of the engine according to claim 2, wherein the communication hole has a diameter smaller than a diameter of each of the first hole and the second hole; a boundary portion between the first hole and the communication hole includes a tapered surface that decreases in diameter toward the communication hole; and an opening edge of the first end of the second pipe includes a tapered surface that increases in diameter toward the communication hole. 